<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.js" type="text/javascript" ></script>
		<style>
			*{
				margin: 0;
				padding: 0;
			}
			div{
				width: 150px;
				height: 150px;
				background-color: red;
				float: left;
				position: absolute;
				left: 50%;
				margin-left: -75px;
				top: 50%;
				margin-top: -75px;
			}
		</style>
	</head>
	<body>
		<div>啥事是</div>
		
	
	</body>
</html>
